Neutral and anionic silylmethyl complexes of the Group 3a and lanthanoid metals; the X-ray crystal and molecular structure of [Li(thf)4][Yb{CH(SiMe3)2}3Cl](thf = tetrahydrofuran)

Abstract

The neutral [M(CH₂SiMe₃)₃(thf)₂](M = Tb, Er, or Yb; thf = tetrahydrofuran) and the ionic [Li(L)₄]-[MR₄][R = Me₃SiCH₂; when M = Y, Er, or Yb, L₂= Me₂NCH₂CH₂NMe₂(tmed); when M = Y, L = thf], [Li(thf)₄][M(Cl)R₃][M = Er or Yb, R =(Me₃Si)₂CH], and [LiL₂][M(η-C₅H₄SiMe₃)₂Cl₂][L = 0·5 tmed or thf) are reported; their structures are deduced from i.r. and ¹³C and ¹H n.m.r. (M = Y) spectra, conductivity, and in the case of [Li(thf)₄][Yb{CH(SiMe₃)₂}₃Cl], by a single crystal X-ray analysis [l(Yb–C)(av.)= 2·38 Å].